/*
 * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package java.sql;

/**
 * The mapping in the Java programming language of an SQL <code>REF</code>
 * value, which is a reference to an SQL structured type value in the database.
 * <P>
 * SQL <code>REF</code> values are stored in a table that contains
 * instances of a referenceable SQL structured type, and each <code>REF</code>
 * value is a unique identifier for one instance in that table.
 * An SQL <code>REF</code> value may be used in place of the
 * SQL structured type it references, either as a column value in a
 * table or an attribute value in a structured type.
 * <P>
 * Because an SQL <code>REF</code> value is a logical pointer to an
 * SQL structured type, a <code>Ref</code> object is by default also a logical
 * pointer. Thus, retrieving an SQL <code>REF</code> value as
 * a <code>Ref</code> object does not materialize
 * the attributes of the structured type on the client.
 * <P>
 * A <code>Ref</code> object can be stored in the database using the
 * <code>PreparedStatement.setRef</code> method.
 * <p>
 * All methods on the <code>Ref</code> interface must be fully implemented if the
 * JDBC driver supports the data type.
 *
 * @see Struct
 * @since 1.2
 */
public interface Ref {

  /**
   * Retrieves the fully-qualified SQL name of the SQL structured type that
   * this <code>Ref</code> object references.
   *
   * @return the fully-qualified SQL name of the referenced SQL structured type
   * @throws SQLException if a database access error occurs
   * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
   * @since 1.2
   */
  String getBaseTypeName() throws SQLException;

  /**
   * Retrieves the referenced object and maps it to a Java type
   * using the given type map.
   *
   * @param map a <code>java.util.Map</code> object that contains the mapping to use (the
   * fully-qualified name of the SQL structured type being referenced and the class object for
   * <code>SQLData</code> implementation to which the SQL structured type will be mapped)
   * @return a Java <code>Object</code> that is the custom mapping for the SQL structured type to
   * which this <code>Ref</code> object refers
   * @throws SQLException if a database access error occurs
   * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
   * @see #setObject
   * @since 1.4
   */
  Object getObject(java.util.Map<String, Class<?>> map) throws SQLException;


  /**
   * Retrieves the SQL structured type instance referenced by
   * this <code>Ref</code> object.  If the connection's type map has an entry
   * for the structured type, the instance will be custom mapped to
   * the Java class indicated in the type map.  Otherwise, the
   * structured type instance will be mapped to a <code>Struct</code> object.
   *
   * @return a Java <code>Object</code> that is the mapping for the SQL structured type to which
   * this <code>Ref</code> object refers
   * @throws SQLException if a database access error occurs
   * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
   * @see #setObject
   * @since 1.4
   */
  Object getObject() throws SQLException;

  /**
   * Sets the structured type value that this <code>Ref</code>
   * object references to the given instance of <code>Object</code>.
   * The driver converts this to an SQL structured type when it
   * sends it to the database.
   *
   * @param value an <code>Object</code> representing the SQL structured type instance that this
   * <code>Ref</code> object will reference
   * @throws SQLException if a database access error occurs
   * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
   * @see #getObject()
   * @see #getObject(Map)
   * @see PreparedStatement#setObject(int, Object)
   * @see CallableStatement#setObject(String, Object)
   * @since 1.4
   */
  void setObject(Object value) throws SQLException;

}
